I noted that just before the big guy threw the first punch, his shoulder moved back which is a good sign of the incoming punch. Had the other guy not taken his eye off him, and with a bit of training and luck, he may have been able to defend himself. His lack of awareness and flat out stupidity by provoking the incident by 1) running his mouth to begin with and 2) acting all tough when the big dude wasn't around is what, IMO, got him the butt whippin'.

Of course this is pure arm chair quarter backing and speculation. Heck, I suppose he could have offered to buy their pizza and apology to de-escalate the matter. One can only guess. Though I believe had he just not said anything, this would not have happened. At times, it's not WHAT you say, but HOW you say it.